Fuse for ordnance projectiles or bombs



May 27, 1947. G. HONGER 2,421,266

FUSE FOR ORDNANCE PROJECTILES OR BOMBS Filed Oct. 29, 1938 4Sheets-Sheet 1 Fig.1

May 27, 1947. HQNGER 2,421,266

FUSE FOR ORDNANCE PROJECTILES OR BOMBS Filed Oct. 29, 1938 4Sheets-Sheet 2 6 INVENT R Guluo HBNGER May 27, 1947. G. HUNGER 2,421,266

FUSE FOR ORDNANCE PROJECTILES OR'BOMBS Filed Oct. 29, 1958 4Sheets-Sheet 5 ATTYS.

y l947- 'e. HDNGER 2,421,266

FUSE FOR ORDNANCE PRQJECTILES OR BOMBS Filed Oct. 29, 1938 4Sheets-Sheet 4 Gumo HA/GER.

ATTYS.

Patented May 27, 1947 UNHTED STATES FUSE FOR ORDNANCE PROJECTILES RBOMBS Application October 29, 1938, Serial No. 237,729

- In Switzerland November 6, 1937 9 Claims.

The invention relates to safety devices incorporated in the fuses ofordnance projectiles and bombs for the purpose of preventing prematureignition.

Such safety devices may broadly be divided into two groups, one forpreventing ignition during transport and handling and the other forpreventing premature ignition in the barrel of the gun or during aportion of the projectiles flight.

A common device is to use a bolt which is by inertia or centrifugalforce, due to the flight of the projectile, removed from a position inwhich it restrains the exploder system from functioning. Devices of thistype must be specially designed for each type of fuse for which they areintended, and the careful and extensive tests required for each designrender this a very expensive matter.

For rendering the exploder system incapable of action during apredetermined portion of the flight of the projectile it is commonpractice to use an escapement that is, a. clockwork mechanism includingan escapement device controlling the turning of its gears, which comesinto operation when the shot is fired or the bomb is released so thatafter a predetermined period a lock which renders the exploder systeminoperative is put out of action. The devices whereby such escapementsare released are frequently sensitive to shocks such as may occur duringthe handling of the projectile, and an accidental shock may then startthe escapement, generally without this being perceived. The safetydevice is accordingly either put wholly out of action, so that theprojectile is in what is called the armed state, or the armed statewill, owing to the partial operation of the escapement, be establishedearlier than expected after the firing of the gun. In either case aserious accident is liable to occur. In the case of some escapements thecumulative effect of a series of small shocks may render the safetydevice inoperative.

In the safety device of my invention two methods of insuring safety arecombined, and the device is one which can be incorporated in a fuse ofany type. The device is so constituted that for putting it out ofaction, so that the exploder system can function, it is necessary thattwo forces should come into operation, namely acceleration due to firingthe projectile and a second, force which may be centrifugal force due tothe spin of the projectile or the force of a spring released by thedischarge of the projectile.

The centrifugal force, or the spring referred to, removes from the pathof a detonating member of the fuse a locking membe which in the safetyposition lies in that path, and the movement of the said locking memberis controlled by a reversible escapement or clockwork mechanism.Movement of the locking member itself from the safety position is,however, normally prevented by a spring loaded bolt, which does notrelease the lockin member till it has by the acceleration of theprojectile been removed from its normal position. This bolt, and thatpart of the locking member which it engages, are so constituted that ifa blow or shock causes relative movement of the locking member and bolt,so that the locking member is moved some way towards the off position,the return of the bolt to its normal position causes the locking memberto be pushed back or rotated back to the safety position, the escapementbeing at the same time restored to its original condition.

Two embodiments of the invention are shown by way of example in theaccompanying drawing, in Figs. 1 to 4 and Figs. 5 to 8 respectively.

Fig. 1 is an axial section showing the safety device and the relevantparts of the exploder system, the safety device being in operation.

Fig. 2 is a section of the line II-II of Fig. 1.

Fig. 3 is a section similar to Fig. 1, but on a smaller scale, showingthe safety device somewhat removed from its operative position, butstill capable of returning automatically to that position.

Fig. 4 is a section similar to Fig. 3, showing the safety device fullyremoved from its operative to its inoperative position.

Figs. 5 to 8 are views similar to Figs. 1, 2, 3 and 4 respectively,showing the second embodiment referred to, Fig. 6 being a, section onthe line VIVI of Fig. 5.

Fig. 9 is a sectional view of Fig. 1 through the escapement mechanismtaken on line 9-9 of Fig. 1.

Referrin first to Figs. 1 to 4, the striker I0 is normally restrainedfrom moving towards the detonating pellet H by a rack it. The teeth IZaof the rack engage one of the wheels lZ'b of the gear train of anescapement or clockwork mechanism l3 holding the rack in the positionshown in Fig. 1. The holder it of the pellet It is likewise prevented bythe rack from moving towards the striker Iii.

The spin of the projectile when it has been fired causes the rack toslide radially outwards, as indicated in.Figs. 3 and 4, with a movementretarded by the escapement, but such radial outward movement cannot takeplace till a bolt formed by a tongue on an annular weight l5 has byinertia been removed from the path of the rack, against the action of acoiled spring I6.

When the tongue has been fully withdrawn from the path of the rack theweight [5 is automatically retained in its retracted position by theexpansion of a compressed split elastic ring ll. After the weight isdisplaced to its retracted position its upper edge is below the loweredge of the compressed ring I! so that the latter will expand to ablocking position as shown in Fig. 4. The fuse is then in the conditioncalled armed, the exploder system being free to come into action at theproper time.

In the course of handling the projectile the same may receive anaccidental blow or shock which causes movement of the weight 5 5 againstthe action of the spring I6, and also causes an outward impulse to begiven to the rack [2. A blow in the direction from the top right handcorner to the bottom left hand corner of Fig. 1 might, for example, dothis. This may cause the weight, with its tongue, to be retracted to theposition shown in Fig, 3, and as the rack has an inclined face 13abutting against an inclined face IQ of the tongue the rack may move ashort distance outwards, as shown in Fig. 3, but this outward movementwill, owing to the action of the escapement, be much slower than themovement of the weight, so that when the impulse which has moved theweight is spent the spring I6 will push the weight back before the rackhas moved across the path of the tongue. The action of the tonguesurface i9 against the rack surface l8 .then forces the rack back to thesafety position, the escapement spring being by this means rewound.Consequently the effect of a series of shocks will not be cumulative inrespect of releasing the escapement, and there is no substantial risk ofthe safety device being ineffective when the projectile is fired.

It will be understood that in the case of a projectile which is to befired from a gun which imparts no spin the rack may be actuated by aspring, no centrifugal force being available for its actuation. Theescapement then serves to check the relaxation of the spring, instead ofto check the winding of a spring.

In the embodiment of the invention shown in Figs. 5 to 8 the function ofthe rack described with reference to Figs. 1 to 4 is performed by thetime wheel 20, of the reversible escapement, and movement thereof is, inthe safety position, prevented by a tongue on an annular weight 2!guided in the plate 22. The inclined surface E9 of this tongue operatesto impart rotational movement to the time wheel when the weight isrestored to the safety position after being displaced by an accidentalshock, instead of impar-ting radial movement, as does the tonguedescribed with reference to Figs, 1 to 5.

The parts H], H, l3, l6 and H shown in Figs. 5 to 8 are equivalent to,and operate in the same way, as the parts bearing the same referencenumerals in Figs. 1 to 5.

It will be understood that the safety device of my invention can beapplied to fuses of all kinds used in connection with ordnanceprojectiles and bombs, that is to say percussion fuses, graze or checkaction fuses, time fuses, combined percussion and time fuses and so on.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is:

-1. The combination, with a projectile fuse having a movable detonatormember, of a movable lockin member adapted to prevent actuation of saiddetonator member, a reversible horological escapement controlling themovement of said locking member, and a spring loaded bolt which normallyprevents movement of said locking member from the locking position andis retracted against the action of its spring by the effect of inertiawhen the fuse is in flight, said locking member and said bolt havingcoacting cam surfaces with a mechanical advantage in favor of the boltwhereby said locking member is restored to the locking position by saidbolt when said bolt, after partial retraction, is restored to normalposition by its spring.

2. The combination, with a projectile fuse having a movable detonatormember, of a radially movable locking member adapted to preventactuation of said detonator member, a reversible horological escapementcontrolling the movement of said locking member, and a spring loadedbolt which normally prevents movement of said locking member from thelocking position and is retracted against the action of its spring bythe effect of inertia when the fuse is in flight, .said locking memberand said bolt having coacting cam surfaces with a mechanical advantagein favor of the bolt whereby said locking member is restored to thelocking position by said bolt when said bolt, after partial retraction,is restored to normal position by its spring.

3. The combination, with .a projectile fuse having a movable detonatormember, of a rotatable locking member adapted to prevent actuation ofsaid detonator member, a reversible horological escapement controllingthe rotation of said looking member, and a spring loaded bolt which normally prevents movement of said locking .member from the lockingposition and is retracted against the action of its spring by the effectof inertia when the fuse is in flight, said locking member and said bolthaving 'coacting cam surfaces with a mechanical advantage in favor ofthe bolt whereby said locking member is restored to the locking positionby said bolt when said bolt, after partial retraction, is restored tonormal position by its spring,

4. The combination, with a projectile fuse having a movable detonatormember, of a movable locking member adapted to prevent actuation of saiddetonator member, a reversible horological escapement controlling themovement of said locking member to release the detonator member at apredetermined time after firing the projectile, a spring-loaded boltwhich normally prevents movement of said locking member from the lockingposition and is retracted against the action of its spring by the effectof inertia when the fuse is in flight, said locking member and said bolthaving coacting cam surfaces with a mechanical advantage in favor of thebolt whereby said locking member is restored to the locking position bysaid bolt when said bolt, after partial retraction, is restored tonormal position by its spring, a, cylindrical support, said boltcomprising a tubular member axially .slidable on said cylindricalsupport, said support having an an- .nular recess therein, and acompressed expansible ring in said recess, said ring being retained inthe recess by the tubular member, and being releasable when said bolt isin its retracted position, and serving to block movement of the boltfrom its retracted position.

5. The combination, with a projectile fuse having a movable detonatormember, of a movable locking member adapted to prevent actuation of saiddetonator member, a reversible horological escapement controlling themovement of said locking member to release the detonator member at apredetermined time after firing the projectile, and a spring-loaded boltwhich normally prevents movement of said locking member from the lockinposition and is retracted against the action of its spring by the effectof inertia when the fuse is in flight, said bolt having a wedgelikeportion engaging the locking member for blocking movement of the lockingmember and for imparting movement to the latter upon displacement of thewedge-like portion relative to said locking member whereby said lockingmember is restored. to the locking position by said bolt when saidbo1t,'after partial retraction, is restored to normal position by itsspring.

6. The combination, with a projectile fuse having a movable detonatormember, of a radially movable locking member adapted to preventactuation of said detonator member, a reversible horological escapementcontrolling the movement of said locking member to release the detonatormember at a predetermined time after firing the projectile, and aspring-loaded bolt which normally prevents movement of said lockingmember from the locking position and is retracted against the action ofits spring by the efiect of inertia when the fuse is in flight, saidbolt having a wedge-like portion engaging the locking member forblocking movement of the locking member and for imparting movement tothe latter upon displacement of the wedge-like portion relative to saidlocking member whereby said locking member is restored to the lockingposition by said bolt when said bolt, after partial retraction, isrestored to normal position by its spring.

'7. The combination, with a projectile fuse having a movable detonatormember, of a rotatable locking member adapted to prevent actuation ofsaid detonator member, a reversible horological escapement controllingthe rotation of said looking member to release the detonator member at apredetermined time after firing the projectile, and a spring-loaded boltwhich normally prevents movement of said locking member from the lockingposition and is retracted against the action of its spring by the effectof inertia when the fuse is in flight, said bolt having a wedge-likeportion engaging the locking member for blocking movement of the lockingmember and for imparting movement to the latter upon displacement of thewedge-like portion relative to said locking member whereby said lockingmember is restored to the locking position by said bolt when said bolt,after partial retraction, is restored to normal position by its spring.

8. The combination, with a projectile fuse having a movable detonatormember, of a movable locking member adapted to prevent actuation of saiddetonator member, a reversible horological escapement controlling themovement of said locking member to release the detonator member at apredetermined time after firing the projectile, and a spring-loaded boltwhich normally prevents movement of said locking member from the lockingposition and is retracted against the action of its spring by the effectof inertia when the fuse is in flight, a cylindrical support, said boltcomprising a tubular member axially slidable on said cylindrical supportbeneath the looking member, a tongue carried. by said bolt andprojecting up in the path of release movement of the locking member,said tongue having a surface cooperating with the locking member fortransmitting movement of the bolt under the action of its spring tomovement of the locking member to its locking position 9. Thecombination, with a projectile fuse having a movable detonator member,of a movable locking member adapted to prevent actuation of saiddetonator member, a reversible horological escapement controlling themovement of said locking member to release the detonator member at apredetermined time after firing the projectile, a spring-loaded boltwhich normally prevents movement of said locking member from the lockingposition and is retracted against the action of its spring by the effectof inertiawhen the fuse is in flight, a cylindrical support, said boltcomprising a tubular member axially slidable on said cylindrical supportbeneath the locking member, a tongue carried by said bolt and projectingup in the path of release movement of the locking member, said tonguehaving a surface cooperating with the locking member for transmittingmovement of the bolt under the action of its spring to movement of thelocking member to its locking position and means operable upon completeretraction of the bolt for retaining it in its retracted position.

GUIDO HCSNGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,182,488 Janney May 9, 19161,726,325 Varaud Aug. 27, 1919 2,116,820 Birkigt May 10, 1938 FOREIGNPATENTS Number Country Date 125,401 Great Britain Apr. 24, 1919

